package test;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class Main {
    public static void main(String[] args){
        int a = -2;
        for (int i=0;i<=32;i++){
            System.out.println("i="+i+" 移动后" +(a<<i));
            System.out.println("i="+i+" →移动后" +(a>>i));
        }
        Map  map = new HashMap();
        Set set = map.entrySet();
        set.iterator();
    }
}
